3. Sailors use a capstan (shown below) to raise and lower the anchor. It takes two sailors located 1 meter from the center to turn the capstan.
How far from the center would one sailor have to be to turn the capstan by himself?
A 1 meter
B. 2 meters
C.3 meters
D. Both B and C would work

B. 2 meters.

Explanation:

To rotate the capstan a certain amount of torque is required, and if each sailor applies a force at a distance from the center, then for two sailors the total torque will be

;

therefore,  for one sailor to apply the same torque it must be that the torque he applies must be equal to the torque that the two sailors applied:

which gives

.

and since ,

which is choice B.